The Critical View of Safety: Case Variations in Lap Chole
by Brie Eteson, Medical Communications, Digital Surgery
What To Do When Things Get Complicated
The latest simulation from Touch Surgery™, available for free in-app, demonstrates case variations on Laparoscopic Cholecystectomy. This procedure is regularly performed to treat gallbladder disease, trauma, cancer, inflammation, and complications of gallstones.1
The first module of this simulation depicts the key steps of a standard case, with emphasis on safe dissection of the hepatobiliary triangle, or Calot’s triangle, to reach the critical view of safety (CVS). The additional four modules explore more complicated cases, including a cirrhotic liver, dissection of Calot’s triangle with a prominent hump of the right hepatic artery, a remnant gallbladder dissection with gallstone and biliary stent resection, and a subtotal cholecystectomy.
This simulation was authored by Saxon Connor, HPB surgeon at Christchurch Hospital, New Zealand, and Tom Hugh MD, Professor of Surgery and Chair of Surgery at Northern Clinical School, Australia.
The critical view of safety
Cholecystectomies have been performed laparoscopically for over 30 years, however, the rate of incidents has remained at 1.5 to 3 per 1000 cases.2,3 Incidents often involve bile duct injuries, which can require intervention, and result in an increased risk of mortality and a diminished quality of life.
Misidentification of biliary anatomy is the most common cause of biliary injury.2,3,4 One way to limit this type of complication is by using the critical view of safety, an identification method to locate the cystic duct and the cystic artery before the cystic duct is ligated and divided.
This simulation demonstrates an example of how to safely attain the critical view of safety and explains what to do when it is no longer safe to obtain the view.
For a standard procedure, the patient is positioned in reverse Trendelenburg, with a 10°–20° tilt post port insertion. An abdominal laparoscopy is then performed. The fundus of the gallbladder should be pushed superiorly and retracted to expose the porta hepatis. Hartman’s pouch (the infundibulum) should then be retracted toward the falciform ligament to maximize the surface area of the hepatobiliary triangle. Rouviere’s sulcus should be identified prior to commencing the dissection of Calot’s triangle.
Rouviere’s sulcus marks the posterior right portal pedicle. Between the sulcus and the base of liver segment 4b, there is a line visible. This line acts as a guide to safely dissecting the posterior hepatobiliary triangle. Dissecting below this line is dangerous.
The authors suggest starting the dissection of Calot’s triangle from the posterior side, until the cystic artery is visualized. The anterior peritoneum is then exposed by retracting Hartmann’s pouch toward the right iliac fossa. The dissection is complete when the anterior peritoneum is completely dissected, and two windows have been created between the cystic duct, cystic artery and cystic plate. These two windows allow the critical view of safety to be confirmed.
The critical view of safety can be confirmed when the lower third of the gallbladder is completely dissected, the cystic artery and duct are delineated, the cystic plate is exposed, and all tissues are cleared.
To learn about how to perform the rest of a typical laparoscopic cholecystectomy, head over to the Touch Surgery™ app and search for Laparoscopic Cholecystectomy Case Variations.
Case Variations and Complications
Patient with cirrhotic liver
If a patient has a cirrhotic liver, a preoperative computerized tomography (CT) scan should be taken as a roadmap for varices.
Key points and differences:
- Port placement is particularly important to avoid visible varices.
- If dissection is unsafe due to inflammation and varices, the procedure may require conversion to a subtotal cholecystectomy.
- Energy devices can be used to minimize bleeding from varices.
- Confirming the critical view of safety is crucial to the continuation of the procedure.
Prominent hump of the right hepatic artery
Dissection of Calot’s triangle with a prominent hump of the right hepatic artery
In cases where the right hepatic artery is prominent, it is important to perform careful dissection of the right hepatic artery until the cystic artery can be identified branching off toward the gallbladder.
Key points and differences:
- During dissection of Calot’s triangle, the hump of the right hepatic artery should be identified.
- Following identification of the prominent hump, dissection of the peritoneum should be performed around the cystic artery branching off the right hepatic artery.
- Observation of the critical view of safety should be possible after completing the above steps.
Remnant gallbladder dissection with gallstone and biliary stent resection
This module depicts a patient who has previously undergone a subtotal cholecystectomy for acute cholecystitis. The patient also previously received an endoscopic retrograde cholangiopancreatogram (ERCP). In this procedure, the surgical team removes the remnant stone and biliary stent, and oversews the junction of Hartmann’s pouch and the cystic duct.
Key points and differences:
- Identification of the remnant Hartmann’s pouch is essential to this procedure.
- After successfully mobilizing the Hartmann’s pouch, an opening should be created in the remnant gallbladder.
- The opening in the remnant gallbladder allows retrieval of any gallstones and removal of the biliary stent to occur.
- Following retrieval, an intraoperative cholangiogram should be performed to ensure there are no more remnant stones.
- The remnant Hartmann’s pouch is closed. The resected gallstones and biliary stent are removed using a specimen bag.
Remnant Hartmann’s pouch with previously placed clip
Gallbladder mucosa and impacted gallstone
The patient shown in this module has Mirizzi syndrome, a rare condition that causes obstruction to the common bile duct or common hepatic duct by external compression from impacted gallstones in Hartman’s pouch.3 For this patient, a subtotal cholecystectomy was performed. It was deemed unsafe to perform the critical view of safety intraoperatively, due to the extent of inflammation at Calot’s triangle and the cystic duct.
Key points and differences:
- Impacted stones may make it impossible to lift Hartmann’s pouch. In this case, the gallbladder was opened above the level of Hartmann’s pouch to improve the maneuverability of the gallbladder and to visualize the embedded stone.
- To disimpact stones, dissect the gallbladder off the posterior portal pedicle.
- If it is unsafe to attempt the critical view of safety, it is recommended to stop the procedure and to perform a subtotal cholecystectomy instead.
- The posterior wall of the gallbladder and the cystic duct are left in place in a subtotal cholecystectomy.
- Once all stones have been retrieved, a drain should be inserted due to potential bile leak from the cystic duct.
Laparoscopic Cholecystectomy is a tricky business and it doesn’t always go as planned. To learn more about these case variations and how to adapt in the operating room if the critical view of safety cannot be achieved, search for this simulation in the Touch Surgery™ app today.
How to cite this simulation:
Connor S, Hugh T. Laparoscopic Cholecystectomy: Case Variations. Touch Surgery Simulations. http://dx.doi.org/10.18556/touchsurgery/2021.s0180. Published Mar. 31, 2021.
1. Potts 3rd JR. What are the indications for cholecystectomy?. Clevel. Clin. J. Med. 1990;57(1):40-47.
2. Brunt LM, Deziel DJ, Telem DA, et al. Safe Cholecystectomy Multi-society Practice Guideline and State of the Art Concensus Conference on Prevention of Bile Duct Injury During Cholecystectomy. Ann Surg. 2020;272(1):3-23.
3. Connor S, Garden OJ. Bile duct injury in the era of laparoscopic cholecystectomy. Br J Surg. 2006;93(2):158-168. doi: 10.1002/bjs.5266.
4. Sanford DE. An Update on Technical Aspects of Cholecystectomy. Surg Clin North Am. 2019;99(2):245-258.
5. Strasberg SM, Brunt LM. The critical view of safety: why it is not the only method of ductal identification within the standard of care in laparoscopic cholecystectomy. Ann Surg. 2017;265(3):464-5.
6. Jones MW, Ferguson T. Mirizzi Syndrome. StatPearls [Internet]. 2019.